Profiling the Research Landscape on Cognitive Aging: A Bibliometric Analysis and Network Visualization.

Objectives: This study aimed to profile the cognitive aging research landscape from 1956 to 2021. Methods: A total of 3,779 documents were retrieved from the Scopus database for the bibliometric analysis and network visualization. By comparing each keyword's overall connection strength (centrality), frequency (density), and average year of publication (novelty) to the calculated median values acquired from the overlay view of the VOSviewer map, the enhanced strategic diagrams (ESDs) were constructed. Results: The findings showed an increasing trend in the number of publications. The United States leads the contributing countries in cognitive aging research. The scientific productivity pattern obeyed Lotka's law. The most productive researcher was Deary, I. J., with the highest number of publications. The collaborative index showed an increasing trend from 1980 onwards. Frontiers in Aging Neuroscience is the most prestigious journal in the field of cognitive aging research. In Bradford core journals zone 1, the top 10 core journals of cognitive aging research provided more than half of the total articles (697, or 55.36 percent). Conclusions: For the next decades, the trending topics in cognitive aging research include neuropsychological assessment, functional connectivity, human immunodeficiency virus (HIV), decision-making, gender, compensation, default mode network, learning and memory, brain-derived neurotrophic factor (BDNF), obesity, D-galactose, epigenetics, frailty, mortality, mini-mental state examination (MMSE), anxiety, and gait speed.

Bitter Gourd Honey Ameliorates Hepatic and Renal Diabetic Complications on Type 2 Diabetes Rat Models by Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Mechanisms.

Honey has several pharmacological effects, including anti-diabetic activity. However, the effectiveness of bitter gourd honey (BGH) in the treatment of diabetes mellitus (DM) is unknown. The aim of this study was to determine the antioxidant, anti-inflammatory, and anti-apoptotic properties of BGH on the kidney and liver of a streptozotocin-induced diabetes rat model. METHODS: A single dose (nicotinamide 110 mg/kg, streptozotocin (STZ) 55 mg/kg, intraperitoneal (i.p.)) was used to induce DM in male rats. For 28 days, normal or diabetic rats were administered 1 g/kg/day and 2 g/kg/day of BGH orally. After the treatment, blood, liver, and kidney samples were collected and analysed for biochemical, histological, and molecular parameters. In addition, liquid chromatography-mass spectrometry (LC-MS) was used to identify the major bioactive components in BGH. RESULTS: The administration of BGH to diabetic rats resulted in significant reductions in alanine transaminase (ALT),aspartate aminotransferase (AST), creatinine, and urea levels. Diabetic rats treated with BGH showed lesser pathophysiological alterations in the liver and kidney as compared to non-treated control rats. BGH-treated diabetic rats exhibited reduced levels of oxidative stress (MDA levels), inflammatory (MYD88, NFKB, p-NFKB, IKKß), and apoptotic (caspase-3) markers, as well as higher levels of antioxidant enzymes (SOD, CAT, and GPx) in the liver and kidney. BGH contains many bioactive compounds that may have antioxidative stress, anti-inflammatory, and anti-apoptotic effects. CONCLUSION: BGH protected the liver and kidney in diabetic rats by reducing oxidative stress, inflammation, and apoptosis-induced damage. As a result, BGH can be used as a potential therapy to ameliorate diabetic complications.

Effect of Antihypertensive Drug Treatment on Oxidative Stress Markers in Heart of Spontaneously Hypertensive Rat Models.

Oxidative stress has been suggested to play a role in hypertension- and hypertension-induced organ damage. The effect of antihypertensive drug treatments on oxidative stress markers has not been well assessed. Therefore, in this study we investigated the effect of enalapril on oxidative stress markers in hearts of hypertensive rat models such as spontaneously hypertensive rats (SHR) and SHRs administered N-nitro-L-arginine methyl ester (SHR+L-NAME rats). Male rats were divided into four groups: SHRs, SHR+enalapril (SHR-E) rats, SHR+L-NAME rats, SHR+enalapril+L-NAME (SHRE+L-NAME) rats. Rats (SHREs) were administered enalapril (30 mg kg-1 day-1) in drinking water from week 4 to week 28 and L-NAME (25 mg kg-1 day-1) from week 16 to week 28 in drinking water. At the end of 28 weeks, animals were sacrificed, and their hearts were collected for the assessment of oxidative stress markers and histological examination. Enalapril treatment significantly enhanced the total antioxidant status (TAS) (P < 0.001), reduced the oxidized glutathione ratio (GSH : GSSG) (P < 0.001), and reduced to thibarbituric acid reactive substances (TBARS) (P < 0.001) and protein carbonyl content (PCO) (P < 0.001), which thus reduced the oxidative stress in the heart. The fibrosis areas in SHRs and SHR+L-NAME rats were also markedly reduced. These findings suggest that enalapril might play a protective role in hypertension- and hypertension-induced organ damage.

Upregulation of catalase and downregulation of glutathione peroxidase activity in the kidney precede the development of hypertension in pre-hypertensive SHR.

Although oxidative stress has been implicated in the pathogenesis of hypertension in spontaneously hypertensive rats (SHRs), there is little information on the levels of primary antioxidant enzymes status (AOEs) in pre-hypertensive SHR. This study therefore determined the activities of primary AOEs and their mRNA levels, levels of hydrogen peroxide (H2O2), malondialdehyde (MDA) and total antioxidant status (TAS) in whole kidneys of SHR and age-matched Wistar-Kyoto (WKY) rats aged between 2 and 16 weeks. Compared with age-matched WKY rats, catalase (CAT) activity was significantly higher from the age of 2 weeks (P<0.001) and glutathione peroxide (GPx) activity was lower from the age of 3 weeks (P<0.001) in SHR. CAT mRNA levels were significantly higher in SHR aged 2, 4, 6 and 12 weeks. GPx mRNA levels were significantly lower in SHR at 8 and 12 weeks. Superoxide dismutase activity or its mRNA levels were not different between the two strains. H2O2 levels were significantly lower in SHR from the age of 8 weeks (P<0.01). TAS was significantly higher in SHR from the age of 3 weeks (P<0.05). MDA levels were only significantly higher at 16 weeks of age in the SHR (P<0.05). The data suggest that altered renal CAT and GPx mRNA expression and activity precede the development of hypertension in SHR. The raised CAT activity perhaps contributes to the higher TAS and lower H2O2 levels in SHR. In view of these findings, the precise role of oxidative stress in the pathogenesis of hypertension in SHR needs to be investigated further.

Protective effect of honey against cigarette smoke induced-impaired sexual behavior and fertility of male rats.

Cigarette smoking is associated with sexual dysfunction and impaired fertility in males. The aim of this study was to determine the potential protective effect of honey against the toxic effect of cigarette smoke (CS) on sexual behavior and fertility of male rats. Thirty-two adult Sprague-Dawley rats were randomly divided into four groups (8 rats/group) as control, honey (H), CS and H plus CS (H + CS) groups. Rats in control and CS groups received oral administration of distilled water daily while rats in H and H + CS groups received honey (1.2 g/kg body weight/day) by oral gavage. Rats in CS and H + CS groups were also exposed to CS for 8 min 3 times/day. From 10 to 13 weeks of treatment, each male rat was cohabited with 3 untreated female rats for sexual behavioral and reproductive performance studies. Honey significantly increased the percentages of rats achieving intromission and ejaculation as well as increased mating and fertility indexes of male rats exposed to CS. Thus, honey has a protective effect against CS-induced impaired sexual behavior and fertility in male rats.

Evaluation of the protective effects of tocotrienol-rich fraction from palm oil on the dentate gyrus following chronic restraint stress in rats

Exposure to chronic restraint stress has been shown to cause a number of morphological changes in the hippocampal formation of rats. Tocotrienol, an isoform of vitamin E, exhibits numerous health benefits, different from those of tocopherol. Recent studies have demonstrated that tocotrienol prevents stress-induced changes in the gastric mucosa, thus indicating that it may also protect other organs such as the brain from the damaging effects of stress. Therefore, the aim of the present study was to investigate the protective effect of tocotrienol-rich fraction (TRF) extracted from palm oil on the dentate gyrus of rats following exposure to chronic restraint stress. Thirty-six male Sprague Dawley rats were divided into four groups: control, stress, tocotrienol and combination of stress and tocotrienol. Animals were stressed by restraining them for 5 hours every day for 21 consecutive days. TRF was administered via oral gavage at a dose of 200 mg/kg body weight. Our results showed that the plasma corticosterone level was significantly increased in response to stress, compared to the control. The results confirmed previous findings that chronic restraint stress suppresses cellular proliferation and reduces granule cell number in the dentate gyrus. However, TRF supplementation failed to prevent or minimize these stress-induced changes. Therefore, we conclude that TRF at the current dosage is not effective in preventing the morphological changes in the dentate gyrus induced by chronic restraint stress.

A exposição crônica ao estresse por restrição causa série de alterações morfológicas na formação do hipocampo de ratos. Tocotrienol, uma isoforma da vitamina E, apresenta inúmeros benefícios para a saúde, diferente do tocoferol. Estudos recentes demonstraram que o tocotrienol impediu alterações induzidas por estresse na mucosa gástrica, indicando, assim, a possibilidade de que ele pode, também, proteger outros órgãos, como o cérebro, dos efeitos nocivos do estresse. Dessa forma, o objetivo do presente estudo foi investigar o efeito protetor da fração rica em tocotrienol (TRF), extraída do óleo de palma, no giro denteado após exposição crônica ao estresse por restrição. Trinta e seis ratos machos Sprague Dawley foram divididos em quatro grupos: controle, estresse, tocotrienol e combinação de estresse e tocotrienol. Os animais foram estressados por restrição, 5 horas por dia, durante 21 dias consecutivos. TRF foi administrado por gavagem oral na dose de 200 mg/kg de peso corporal. Nossos resultados mostraram que o nível de corticosterona plasmática foi significativamente aumentado em resposta ao estresse em comparação ao controle. Os resultados confirmam os achados anteriores de que o estresse por restrição suprime a proliferação celular e reduz o número de células granulares do giro denteado. No entanto, a suplementação de TRF foi ineficaz para evitar ou minimizar as alterações induzidas por estresse. Assim, concluímos que TRF na dose corrente não é efetiva para prevenir as alterações morfológicas no giro denteado induzida por estresse crônico por restrição.

Antioxidant protective effect of honey in cigarette smoke-induced testicular damage in rats.

Cigarette smoke (CS) can cause testicular damage and we investigated the possible protective effect of honey against CS-induced testicular damage and oxidative stress in rats. CS exposure (8 min, 3 times daily) and honey supplementation (1.2 g/kg daily) were given for 13 weeks. Rats exposed to CS significantly had smaller seminiferous tubules diameter and epithelial height, lower Leydig cell count and increased percentage of tubules with germ cell loss. CS also produced increased lipid peroxidation (TBARS) and glutathione peroxidase (GPx) activity, as well as reduced total antioxidant status (TAS) and activities of superoxide dismutase (SOD) and catalase (CAT). However, supplementation of honey significantly reduced histological changes and TBARS level, increased TAS level, as well as significantly restored activities of GPx, SOD and CAT in rat testis. These findings may suggest that honey has a protective effect against damage and oxidative stress induced by CS in rat testis.